A gamma-ray polarimeter based on a single segmented planar HPGe detector
2008 (English)In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, ISSN 0168-9002, Vol. 593, no 3, 459-465 p.Article in journal (Refereed) Published
The polarization sensitivity of a segmented planar HPGe detector has been measured. For this purpose 662 keV photons from a Cs-137 source which were Compton scattered at approximate to 90 degrees in a coaxial germanium detector were utilized as a source of partially linearly polarized gamma radiation of the energy; approximate to 288 keV. The detector has a 50 x 50 x 21 mm sensitive volume and 5 x 5 electrical segmentation of the cathode contact. The degree of linear polarization is determined through the analysis of the directions of Compton scatterings inside the detector. The locations of the Compton scattering interactions and of the subsequent photo-absorption interactions have been determined with the help of pulse shape analysis (PSA), provided that these interactions are in two different segments of the planar detector. A comparison with a polarization analysis using the position resolution defined by the physical segmentation (without the use of PSA) was also performed. It is demonstrated that the use of PSA enables a much higher polarization sensitivity for events where the 288 keV photons scatter between adjacent pixels. Such events constitute 90% of the data for the 288 keV photons and are even more important for gamma-rays of lower energies.
Place, publisher, year, edition, pages
2008. Vol. 593, no 3, 459-465 p.
polarization, segmented planar germanium detector, pulse shape analysis, matrix method
IdentifiersURN: urn:nbn:se:kth:diva-7862DOI: 10.1016/j.nima.2008.05.063ISI: 000259120700030ScopusID: 2-s2.0-47849098320OAI: oai:DiVA.org:kth-7862DiVA: diva2:13012
QC 201011102007-12-192007-12-192010-11-10Bibliographically approved